www.pudn.com > VAD-DTW-HMM.rar > dtw2.m

function dist = dtw(test, ref) 
global x y_min y_max 
global t r 
global D d 
global m n 
 
t = test; 
r = ref; 
n = size(t,1); 
m = size(r,1); 
 
d = zeros(m,1); 
D =  ones(m,1) * realmax; 
D(1) = 0; 
 
% 如果两个模板长度相差过多，匹配失败 
if (2*m-n<3) | (2*n-m<2) 
	dist = realmax; 
	return 
end 
 
% 计算匹配区域 
xa = round((2*m-n)/3); 
xb = round((2*n-m)*2/3); 
 
if xb>xa 
	%xb>xa, 按下面三个区域匹配 
	%        1   :xa 
	%        xa+1:xb 
	%        xb+1:N 
	for x = 1:xa 
		y_max = 2*x; 
		y_min = round(0.5*x); 
		warp 
	end 
	for x = (xa+1):xb 
		y_max = round(0.5*(x-n)+m); 
		y_min = round(0.5*x); 
		warp 
	end 
	for x = (xb+1):n 
		y_max = round(0.5*(x-n)+m); 
		y_min = round(2*(x-n)+m); 
		warp 
	end 
elseif xa>xb 
	%xa>xb, 按下面三个区域匹配 
	%        0   :xb 
	%        xb+1:xa 
	%        xa+1:N 
	for x = 1:xb 
		y_max = 2*x; 
		y_min = round(0.5*x); 
		warp 
	end 
	for x = (xb+1):xa 
		y_max = 2*x; 
		y_min = round(2*(x-n)+m); 
		warp 
	end 
	for x = (xa+1):n 
		y_max = round(0.5*(x-n)+m); 
		y_min = round(2*(x-n)+m); 
		warp 
	end 
elseif xa==xb 
	%xa=xb, 按下面两个区域匹配 
	%        0   :xa 
	%        xa+1:N 
	for x = 1:xa 
		y_max = 2*x; 
		y_min = round(0.5*x); 
		warp 
	end 
	for x = (xa+1):n 
		y_max = round(0.5*(x-n)+m); 
		y_min = round(2*(x-n)+m); 
		warp 
	end 
end 
 
%返回匹配分数 
dist = D(m); 
 
function warp 
global x y_min y_max 
global t r 
global D d 
global m n 
 
d = D; 
for y = y_min:y_max 
	D1 = D(y); 
	if y>1 
		D2 = D(y-1); 
	else 
        D2 = realmax; 
	end 
	if y>2 
		D3 = D(y-2); 
	else 
        D3 = realmax; 
	end 
    d(y) = sum((t(x,:)-r(y,:)).^2) + min([D1,D2,D3]); 
end 
 
D = d;